The present invention relates to a ground station for a round-trip-path distance-measuring system commonly known as a DME (distance-measuring equipment) system.
A DME ground station is known, for example from the text by E. Kramar, entitled "Funksysteme fur Ortung und Navigation," published by Berliner Union GmbH, Stuttgart 1973, pp. 147 to 159.
Distance measurements are necessary both during en-route air navigation and during landing. For en-route navigation, the DME ground stations are colocated with a VOR ground station, for example. By measuring the angle to and the distance from this VOR/DME ground station, the pilot can determine his position relative to this station.
During the landing phase, the pilot needs the aircraft's distance from the touch-down point. That point is, however, along the runway centerline and accordingly no DME ground station can be installed there.